What were both nobles and knights obligated to do? remain loyal to one another protect those who lived on the manor take an oath of chivalry provide personal and military service to the king

In feudalism system of government, the king owned all the land but he granted parts of it to nobles in return for protection, service and loyalty. Besides, the king could also give lands to vassals or knights who were part of the army and provided military assistance. In order to serve the lord’s army, the nobles had to provide knights with weapons, horses, money and food. It was a system of hierarchy. In the last category there were the peasants who worked the lord or knight’s land. Not only nobles but also knights had to take an oath of chivalry and provide personal and military service to the king.

The correct answer is D)  provide personal and military service to the king.

Both nobles and knights were obligated to provide personal and military service to the king.

During feudal times in the Middle Ages, nobles and knights pledge allegiance to the king. They served the king and protect him and the kingdom. In exchange for their loyalty, the king offered them portions of land called fiefs. Knights were good and brave warriors. So the king also gave then money, food, and lodge.

declare war, appoint military officers, sign treaties, make alliances